Softening leather by application of an acetylated monoglyceride



United States Patent 0 3,399,954 SOFTENING LEATHER BY APPLICATION OF ANACETYLATED MON OGLYCERIDE Gerard Warren Curtis, Fair Lawn, N.J.,assignor to American Cyanamid Company, Stamford, 'Conn., a corporationof Maine No Drawing. Filed Mar. 6, 1964, Ser. No. 350,097 1 Claim. (Cl.8-94.22)

ABSTRACT OF THE DISCLOSURE A process is provided for softening agedleather which involves swabbing said leather with either liquidmonoacetyl glycerol dioleate or liquid diacetyl glycerol monooleate.

The present invention relates to an improved process for treatingleather. More particularly, it relates to a process for softening agedleather. Still more particularly, the invention is concerned with animproved process for softening aged leather by the application of anacetylated monoglyceride.

It has been an ever growing concern to leather technologists to preventleather from ultimately hardening and becoming both slippery to thetouch and even brittle due to its tendency to dry out on aging. In allapplications of leather, continued use renders the leather smooth andslippery to the touch, thereby requiring frequent replacement where anon-slippery, slightly tacky and resilient surface is required. Thus, toremedy this situation, various procedures have been suggested in thepast. One such procedure has been to swab aged leather with sulfonated,castor oil and other soaps to restore it. Unfortunately, this procedureis not entirely satisfactory, for the reason that the treatment is notlong lasting. Another procedure is in the application of saddle soap.Any benefit derived therefrom is also short-lived, in that the soapremains on the leather surface for only a short period of time. Thistreatment merely affects the surface. There is no effective penetration.A still further treatment of leather resides in the use of rosinpreparations. Most such rosin preparations contain wax to soften theleather. Again, wax compositions do not ordinarily penetrate leatherbeyond the surface of leather. Further, low melting point waxes arereadily removed by the touch of a warm or perspiring hand. In arelatively short period of time, the rosin preparation-treated leatherreverts to its non-useable state. If a leather-treating material couldbe developed such that it penetrates leather and is long lasting, such acomposition would be highly desirable.

It is, therefore, a principal object of the present invention to providea leather-treating material which can be economically and readilyapplied to leather so as to either maintain its original newness or torestore the same to its original state. It is a further object of theinvention to provide a leather-treating material which can penetrate thesurface of leather and maintain or restore the leather to its originalstate for a prolonged period of time. Other objects and advantages willbe determined from a consideration of the ensuing disclosure.

To this end it has been unexpectedly found that either new leather canbe maintained or aged leather can be restored to its original stateeconomically and rapidly by providing for the topical applicationthereof with an acetylated monoglyceride. The latter being applied as aliquid penetrates the surface of leather upon application.

The invention will be particularly described with respect to agedleather grips on golf clubs. Although the ice leather thereon isfrequently exposed to elevated temperatures and to resultant handperspiration, it is exposed also to low temperatures, even freezingtemperatures. Such exposure clearly falls within the contemplation ofthe avid golfer. In a low temperature environment, gripping of the clubis exceedingly difficult in that it becomes exceedingly slippery but forthe treatment contemplated by the present invention.

When leather on golf clubs is new, it is soft and tacky, therebyproviding for easy gripping of the club. However in time, usually withina year or more, the leather on a golf club becomes unduly slippery,smooth and hard. To restore the leather to its original state, it hasbeen found unexpectedly that an acetylated monoglyceride, comprisingeither diacetylated glycerol monooleate or monoacetylated glyceroldioleate, can be applied to leather by merely swabbing the oleatematerial thereon, and wiping or otherwise removing excess compound.Within not more than about 24 hours, the leather has been restored toits original state. Further, with ordinary use, the leather need not beretreated within an extended period of six months or more. Where theleather is constantly exposed and used, the required period forretreatment is somewhat shortened or reduced, usually to within a monthor two.

As stated above, the acetylated glycerol oleate leathertreating materialemployed herein may be either monoacetyl glycerol dioleate or diacetylglycerol monooleate. In either form, the oleate is a liquid and usuallypossesses an acid number of one or less, a saponification number of375-385, an iodine value of 50-60, an hydroxyl value of over 30, andpercent monoglyceride equal to 1% or less. The diacetyl glycerolmonooleate is prepared by reacting two mols of acetic anhydride with onemol of glycerol monooleate. Similarly, the monoacetyl glycerol dioleateis prepared by reacting one mol of acetic anhydride with one mol ofglycerol dioleate.

Advantageously other liquid acetylated glycerol high fatty acid esterscan be employed. Such high fatty acid esters are, for instance, thosecontaining from 12 to 22 carbon atoms, and more specifically includelaurylates, palmitates, linoleates and equivalents thereof.

Although the invention has been described with respect to the treatmentof leather on a golf club, it advantageously can be applied to thetreatment of leather in general, as for instance, the treatment of theuppers of leather shoes, leather gloves and the like.

I claim:

1. A process for softening aged leather which consists essentially in:swabbing the said aged leather with a treating agent selected from thegroup consisting of liquid monoacetyl glycerol dioleate and liquiddiacetyl glycerol monooleate, said treating agent possessing asaponification number of from 375 to 385, an iodine value of from 5 0 to60 and a percent monoglyceride equal to not more than 1%, and,thereafter, removing any excess treating agent.

Benton: American Perfumer and Cosmetics, vol. 78, pages 38-40, October1963, 167-91.

NORMAN G. TORCHIN, Primary Examiner.

DONALD LEVY, Assistant Examiner.

